Abstract:

Objective: To develop a biosensor for detecting catalase-positive microorganisms in food. Methods: HRP was immobilized onto screen-printed electrodes (SPE) and an analytical system was established by inserting SPE into the electrode slot connected with an electrochemical workstation. Results: For most food samples from different sources, this method allowed detection of positive signals based on current change when the number of catalase-positive microorganism colonies reached up to 104 CFU/mL. The length of time required for food detection was dependent on the number of catalase-positive microorganism colonies and a period of time ranging from 1 to 3 h was enough for the detection of most food samples. Catalase-positive microorganisms contained in food samples at 0.1 CFU/mL needed to be enriched for 7 h, at the longest. Conclusion: This method is convenient, sensitive and accurate, and deserves to be popularized.

Key words: catalase-positive organism, detection, biosensor